Electronic touch panel displays are used in many commercial applications including ATMs, automobiles, informational displays, personal computers, cell phones, and the like. Such displays are advantageous as the content may be easily changed and the displays are interactive. In many applications having an electronic touch panel display is desirable, but in some applications the need for redundancy has slowed the use of such displays.
Examples of such applications include, but are not limited to, commercial aviation, space flight, and military applications, where redundancy measures are demanded to ensure continued performance of equipment in the event of a partial failure. In these and other applications there may also be visibility requirements to ensure performance under extreme environmental conditions. These may include ability to withstand high levels of solar loading and visibility in bright ambient conditions. Such stringent requirements are demanded because of the possible consequences of failure. Therefore, it is desirable to provide an electronic touch panel display meeting visibility requirements and having redundancy measures.
Finally, in these and other applications, electromagnetic interference (EMI) and EMC may become an issue as there are often multiple pieces of electronic equipment operating in close proximity. Each device may emit electromagnetic energy, which can cause EMI with the operation of the other unit that may result in interrupted performance. EMC is the ability for multiple devices to work in the same electromagnetic environment. Therefore, it is additionally desirable to provide the aforementioned electronic touch panel display also having EMC endurance capabilities that limit EMI.
Exemplary embodiments of the present invention may comprise an electronic display housed in a sealed gasket with a resistive touch panel having redundant sensors and input/output devices. The gasket may prevent the display from being compromised by harsh environmental conditions. The display may additionally be comprised of multiple layers adapted to withstand high solar loading and remain visible in high ambient sunlight environments, such as by use of an active matrix liquid crystal display (AMLCD). This display may provide one large, contiguous video image or may provide multiple, independent video images.
The touch panel may comprise circuitry configured to limit EMI and improve EMC. The assembly may additionally comprise shielding between layers of the display and in the channels associated with the display, which also limits EMI and improves EMC.
At least two seamless, adjoining grid sections and corresponding touch sensors capable of determining touch screen input are utilized, thus providing a seamless display and interaction experience when viewed and utilized. This also makes the touch panel redundant. For example, without limitation in the event of a failure of one of the grids or the corresponding sensors, the display may automatically shift to display images only on the portion of the display covered by the remaining operable grid/sensor. Further, at least two input/output devices are utilized to ensure that each portion of the display and touch panel can be driven independently from either input/output device. These two measures provide redundancy and preserve the operability of the display under partial failure.
The display may be made such that it is adapted to comply with military specifications for use in military applications, such as aviation.